SSH: Public Key Creation and Activation

Because ssh servers on the internet are commonly
subject to brute-force password attacks, it is recommended
that you disable password-based logins and use
public/private key authentication. Here's how.

On the local machine, in your home directory's .ssh
subdirectory (which you should create and make only
owner readable/executable if it doesn't exist; e.g by
typing mkdir ~/.ssh && chmod 0700 ~/.ssh), you
should execute the command ssh-keygen -t dsa,
enter a password, and accept the default names for files
(by pressing ENTER).

Before you attempt to connect to remote machine, execute
the command ssh-add.

If you add the package ssh-askpass
or ssh-askpass-gnome on Debian with
GNOME, or on Ubuntu, ssh-add well be executed whenever you login
to your graphical session, meaning you will get a window
asking you to enter your SSH passphrase on login.